Enantiomers, Diastereomers, Or The Same?

[@kenziil7016]

I read the section in my book twice, came to this video...understood it in minutes. Thank you!

[@MasterOrganicChem]

Awesome! thanks for letting me know!

[@AC-qo8oq]

Finally! I get it! Nobody told me to check the R and S to see if they're. I have been staring at them for 20 mins trying to see how.. Thank you!

[@MasterOrganicChem]

check the R and S yes, glad it helped

[@nicoleswanson8579]

Great video! I have been prowling the web for a better understanding and the fact that you didn't talk about the bond rotation truly helped me. THANK YOU!

[@MasterOrganicChem]

Yes! Thanks - everyone talks about bond rotations but it gets complex once a molecule gets big enough - glad you found this alternate method useful!

[@medaphysicsrepository2639]

this is the BEST video for understanding these concepts, you're best work by far! i love it bc the bulk of it is based on examples, and its step by step. giving problems for me to do (and get wrong twice >.< but hey after watching them all I've got it down) makes it a model for how i wish organic chemistry tutorials were

[@MasterOrganicChem]

thank you very much thomas underhill !

[@LittleMissTutuz]

agreed!!!

[@riverremis69]

Been struggling a bit trying to get a solid grip on stereochemistry -- & this seriously helped immensely!

[@MasterOrganicChem]

Glad to hear it. Thanks!

[@swanh6249]

You have the best organic chem videos!!! It's much more helpful than my professor lectures or reading the text book. Thank you so much!! Keep doing your great work :)

[@MasterOrganicChem]

If you found this video helpful, you may want to check out our MOC membership plan, month-to-month / cancel anytime benefits here: bit.ly/2YctxPb

[@nataliearias932]

thank you so much! I've been stuck on this question since I took my stereochemistry test, and you really helped me comprehend what I was missing!

[@gabriellemary]

Saving me for my DAT 8 years later, thank you

[@MasterOrganicChem]

Great to hear!

[@vamparaz]

Thanks for your clear explanation and neat writing, very much appreciated!

[@sanjanakapuria238]

you have literally saved me from a mental breakdown. god bless you sir

[@TheBigSnek]

Lol good luck

[@MasterOrganicChem]

You are so welcome with the help on enantiomers

[@PreetKaur-fk3ds]

Brilliant .... very well explained. Thanks a lot.

[@ononchintuya2668]

honestly i never comment but your videos are sooooooooooooooo helpful that i can not just stay without complimenting your videos

[@MasterOrganicChem]

If you found this video helpful, you may want to check out our MOC membership plan, month-to-month / cancel anytime benefits here: bit.ly/2YctxPb

[@dianethompson58]

This video really helped me understand this concept. Thank you!

[@harshitshukla7208]

Please check If we rotate 3 bonds fixing one in the 2nd molecule, we will get the identical molecules sir. These are identical right?

[@braydenpriebe6157]

What if #4 is in the plane of the screen/paper (solid line)? Is the correct answer R/S still the opposite of what's expected (clockwise/counterclockwise)?

[@Tommy-zu6vb]

I really don't understand the concept of R/S. At 4:46, you see the configuration goes clockwise which means it is R, due to the atom number. And then you say #4 atom which is H, is in front and therefore it suddenly is S??? It is still R when looking at the atomnumbers? I am so confused lost right now...

[@jamesash6233]

The rules say that when the #4 substituent is in the back (dash) , if 1,2 and 3 trace a clockwise path, the stereocenter is R. If 1,2 and 3 trace a counterclockwise path, the stereocenter is S. In our case, the #4 substituent is in the front (wedge). We *could* rotate the molecule so that the normal rules apply, but this is a pain to do on paper and it's easy to make a mistake. Therefore, what I did here was to use the "reverse rules". Since #4 is in the front (wedge) since 1,2 and 3 trace a clockwise path, we use the "reverse" of the rule, and therefore the stereocenter is S. It's a bit like looking in a rear-view mirror. Imagine looking at your friend in a rear-view mirror holding up his right hand, and he asks you what hand he is holding up. Since you know that you are looking in a mirror and the mirror reverses everything, you use the *reverse rules* so you say, "Left!".

[@babyboikal]

At 5:36 for the molecule on the right, why don't you rotate counterclockwise in the direction of the 3rd priority atom first?

[@BleuLou-ok6pg]

Thank you for making R/S plain and simple to understand!!! Quiz this Friday;--)

[@MasterOrganicChem]

Glad you found the R and S understandable~

[@mmmaheesa5946]

Thank you so much sir for your clear explanation !!!🤗🤗

[@MasterOrganicChem]

You are most welcome

[@trentkirkwood4195]

How are they enantiomers? They are not mirror images. I see the connections and the R/S but how does that correlate to being enantiomers when enantiomers have to be mirror images? Non superimposable mirror images I believe correct me on that.

[@yonipool8683]

Thank you for posting this! it really is so helpful !

[@MasterOrganicChem]

You are welcome

[@pinky7209]

amazing clarity

[@rossbeattie8947]

If number 4 is in the front its opposite - why was i never told this?!

[@MasterOrganicChem]

If you look at your left hand in a mirror, it looks like it's your right hand. If you *know* you're looking in a mirror, you can correct for this by using "opposite" rules (right is left, left is right) and therefore you get the correct answer! Same principle! :-)

[@mishraji7848]

Your Vedio is just amazing....loves from IND

[@allbeen]

what do you mean by connectivity ? same atoms ?

[@thinkfi781]

Thanks for helping me to do the questions on enantiomers sir😀😀😀

[@MasterOrganicChem]

It's my pleasure to help you with your questions on enantiomers

[@zaziechapellier4760]

Amazing! Thank you!

[@MasterOrganicChem]

Thank you too!

[@christianalexandermarion]

Explained it better in 7 minutes than my org chem professor ever did at my 40K, a year, university

[@MasterOrganicChem]

Awesome. Thank you!

[@kattran3798]

Can anyone explain? I did my usual way of putting H in the back for the first molecule, but it still goes clockwise for me. I'm not seeing how it would go counter clock wise!

[@rimadevi2011]

Me2🤔

[@MasterOrganicChem]

The way the first molecule is drawn, 1, 2 and 3 priorities *do* go clockwise. However, R/S is always determined with #4 being in the back. Since #4 is in the *front* here, we use "opposite rules". So 1, 2, and 3 going clockwise actually results in an S stereocenter when #4 is in the front. If you make a little model and rotate it around so that you put #4 in the back, you'll see that 1,2 and 3 "magically" now go counter-clockwise. So this little "opposite" trick saves you the time of making models, etc.

[@طبوصيدلة]

oh ! this is realy awesome , thank you MR i understand now and then you save my mark for stereochemistry ^_^ thank you very much

[@Bella24Forever]

I am not sure where the other video you were talking is located

[@MasterOrganicChem]

Which topics were you interested in, I can hel send links

[@GoldCattt]

Thank you

[@MasterOrganicChem]

Welcome!

[@thesolitaryreaper2388]

Sir I have confusion with the 1st compound for me it seems to be R configuration as it is clockwise but you said it's S. Please help me to get rid of this query

[@roseblanche9073]

Hi , when H is in the front , you need to reverse the configuration, it was R clockwise but the H is in the front so reverse it to become S.😊

[@thesolitaryreaper2388]

@@roseblanche9073 I got it, thanks

[@danamclemore3805]

thanks a lot, dude! helpful

[@tiibrahim5714]

Thanks sir u've cured my sickness

[@husseinsa5050]

Thank you sooo much

[@hariommeena7162]

this is really good

[@tadevosmakaryan2378]

Arent they constitutional isomers... however they are better labeled as enantiomers . Doesn't mean they are not constitutional isomers. They are constitutional isomers, not confirmation isomers ( because there is no rotation about a sigma bond) , but are stereoisomers, more specifically enantiomers.

[@01107345]

Enantiomers are mirror images. Two molecules can't be mirror images if they're constitutional isomers.

[@rishabbairagi2904]

Couldn't understand what is R and S.

[@hafizjamshidi251]

Awsome video...Thanks

[@MasterOrganicChem]

thank you glad you found this helpful

[@Zch73]

Great video

[@MasterOrganicChem]

thank you

[@dianethompson58]

How should I should I rotate the molecule if the hydrogen is in the plane of the paper?

[@MasterOrganicChem]

If the H atom is in the plane, here's one tactic that you can do, which employs the "single swap rule". Swapping *any two groups* with each other on a stereocenter, will flip that stereocenter from R to S (or vice versa). Just like looking in a mirror *swaps* the appearance of your left and right hands (your left appears to be right, and your right appears to be left). Knowing this, *swap* the H in the plane with whatever group is in the back (wedge). Redraw. *Then* determine R and S. Once you've determined R and S, you then need to correct for the fact that you did a single swap (just like when looking at your hand in a mirror, you need to correct for the fact that you're looking in a mirror to be able to determine the "correct" hand - it will be the opposite). So the correct R/S value will be whatever is the opposite of the R/S you determined in the swapped version.

[@sravanvenus1180]

thanx a ton... exceptinal explanation... please do help us more

[@MasterOrganicChem]

Thank you for the response, I will be adding more videos and explanations

[@kdagem4217]

But they arent mirror images

[@RoflJoker1994]

i dont understand the first explanation.. its counterclockwise coz 4 is in the front? wut?

[@MasterOrganicChem]

R and S is determined with the #4 group being in the back. In the first example, #4 is in the front. Therefore we can get the same answer if we apply "opposite" rules. Since 1, 2 and 3 proceed in a clockwise direction when #4 is in the front (wedge), they must proceed in a *counter clockwise* direction when #4 is in the back (dash). Therefore we get S.

[@arshitasaini876]

such a good video, thanks :)

[@ononchintuya2668]

so sad that i found these videos after failing on my orgo exam

[@MasterOrganicChem]

thank you so much! Spread the word if you know of others who could find our organic chemistry videos useful!

[@purplejakman]

What if it's above or to the side??????? Only a video for specific problems are terrible

[@MasterOrganicChem]

It is true that if the H is on the side, one cannot use the "opposite" rule. However one can still use the "single swap" rule. Redraw the molecule with the H in the back and the "back" group on the side, and determine R/S as normal. Then flip the result.

[@raghadalhabshi1463]

Oh I love you

[@MasterOrganicChem]

Glad it helped! I would like to invite you to check out our monthly (no long term commitment) membership with over 1500 quizzes, flashcards the reaction guide and more. Here's access: bit.ly/2YctxPb

[@subhendunayak]

Continue

[@MasterOrganicChem]

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[@subhendunayak]

@@MasterOrganicChem I don't want paid plans

[@Kkkkkkkkkkk364]

awsome

[@MasterOrganicChem]

So glad the R and S video was helpful to you

[@asmabibi8846]

ssuuuper

[@purplejakman]

Guys don't listen to his "rule" about switching, I have tried the rule and it does not work, I then showed it to my professors and they said it has no consistency, this guy is a fake 100%

[@purplejakman]

To be more specific if the "front" H was pointing the other way it would not follow this rule, even if it is pointing to the front

[@MasterOrganicChem]

If you flip any two groups on a chiral center it will flip R to S or vice versa. Try it.